Spring locking-washer.



s. W. WILKINSON, w. GREGQRY & E. a. & R. JENKINS.

SPRING LOOKING WASHER.

APPLICATION FILED MAY 15, 1909.

966,973. Patented Aug. 9, 1910.

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gmmw a W SVL'UQA VIIO'tQ wi bl vmw W g Q M Mm "the underside of a nut or other partagainst svnzunir WILLIAM winmnson nnn WALTER GREGORY, or narnnasnen, NEAR 1 SHEFFIELD, AND nnwaaneow'rannr.

nnannnenan'n.

srn rie LOCKING-WASHER.

Specification of Letters Patent. Patented Aug, 9 1910 A neatiba'fiieam 15, 1909. Serial no. 496,289.

To all whom it may, concern:

Be it known that we, SYDNEY WILLIAM WILKINSON, WALTER GREGORY, EDWABDCOT- 'rnnLi. JENKINS, and ROBERT JnNKINs,subjects of the King of Great Britain and Ireland, residing, respectively, near Sheffield, .in the county of Derby, and Birkenhead, in the county of Chester, England, have invented Improvements in Spring Locking-Washers, of which the following is a specification. I y

This invention relates to spring. locking washers for screw bolts, studs, and'the like, and other purposes. v It has heretofore been proposed to manufacture spring washers from strips of ribbon steel the ends of which are tapered or made wedge shape for the purpose of having the bearlng faces of the washer parallel to each other; other coiled washers have also been made of ribbon steel of a uniform cross section throughout, and which to produce par allel bearing faces have had a kink formed therein, in the process of manufacture, thus the helix of the coil was not continuous throughout but joggled at one portion in order to form the kink and consequently sucfha washer is liable to fracture at this ay, v on being tightly compressed. In order i thatl theTends of spring washers shall engage whibhthey bear some such washers have had their ends so formed that they project outwardly. l

Now the'object of this invention is to provide improved washers of this helically 'coiled spring type in which the disadvantages of the constructions heretofore known are obviated without increasing the expense of manufacture.

The outer periphery of a spring locking washer according to this invention retains the ordinary helically wound or screw like form but the intrados, or inner marginal portion thereof, is formed with a kink or slight curvature such that the steel strip or ribbon of which the washer is formed is level at the-ends of the kinked or curved part, that is to say at such parts it extends at right angles to the axis of the bolt or the like it surrounds when in use. The kink or slight curvature is formed within the width of the steel strip or ribbon and vanishes at the outside'edge thereof so at Hathersage,

that the fibers of the metal undergo but slight distortion, and

when the washer is in use its free ends tend to slightly embed themselves in the respective surfacesagainst which they bear.

The improved'spring washer comprises in some. cases more than one complete coil in spring form the end portions of which project outwardly so asto engage with the underside of a nut in a known manner for preventing the nutfroin turning in a direction to become unscrewed. The ends of the washer are out at such an angle that when the washer is hard down said ends will be clear of the kinked or curved portion of the intermediate coil. It will thus be understood that in the event of parts secured together by bolts fitted with the improved.

locking washers becoming slack after the OFFICE.

JENKINS AND ROBERT JENKINS, OF BIRKEN- bolt nuts have been tightened hard up, ow-

ing it may be to deterioration of one or both oi: the parts so secured, the washer will expand to allow for this, but the ends of.

the coil will however still bear tightlyon the nut and prevent it from becoming unscrewed unintentionally.

Figure 1 of the accompanying drawings is a plan of the improved washer. Fig. 2 is an elevation of same in its normal or free position. Fig. 3 shows the improved washer in its normal or free position in central ver tical section, showing the portion of the coil in which the kink is formed as seen from the inside.

The strip of steel or other suitable metal from which the improved spring washers can be made is preferably in ribbon or tape form of an equal cross section throughout.

As will be seen in Fig. 1 the ends a, of the spring are slightly curved, this is caused by the rolling or coiling operation notwithstanding that the ends of the metal strip blank from which the washer is formed are each cut at an angle of 45.

The circumferential distance 7) between the ends is suiticient to allow for the kink or nnnishing to nothing at the outer periphery of the washer as shown 1n Figs. 2 and 3.

The formation of the kink is such that the 7 ends of the washer when the washer is compressed to its full extent tend to press out-" wardly so that they will tend to slightly e1nbed themselves into a nut, or the head of a set screw, and the base on which the washer rests, even when the nut or set screw is partially unscrewed, thus forming a permanent locking washer to ordinary screw threaded.

timber may shrink and with the ordinary spring washer having a fiat bearing surface would allow the nut to become slack, whereas with the improved locking washer when allowed to expand some distance through any cause, the ends will still be in advance of the body part and bear against the nut and other face, thus preventing unscrewing of the nut through vibration and the like.

Whatwe claim is 1. A spring locking washer formed from a strip of ribbon steel coiled helically, having a kink on the intrados or inner marginal portion thereof and the outer periphery of which is not kinked. v

2. A spring locking washer formed from a strip of ribbon steel coiled helically and having a kink on the intrados or inner marginal portion thereof, said kink being formed within the width of the strip and vanishing at the outer periphery.

3. A locking washer composed of a helically coiled strip of spring metal having its ends arranged adjacent to each other, said strip having a kink at its inner marginal portion and vanishing at the outer eriphery thereof, said kink being located a jacent to said ends and about midway the length of the strip.

Signed by SYDNEY WILLIAM VVILKINsON and W'ALTER GREGORY at Sheffield England this 27th day of April 1909.

SYDNEY WILLIAM WILKINSON. WALTER GREGORY. \Vitnesses:

LUTHER J. PARR, CHAS. N. DANIELS.

Signed at Tower Buildings, Liver 001 this 22nd day of April 1909 by EDWARD OTI'RELL JENKINS and ROBERT J ENKINS.

EDWARD OOT'IRELL JENKINS. ROBERT JENKINS. Witnesses F. M. C. Sco'r'r, H. WILLIAMS. 

